Heretofore, in connecting a plurality electric wires to each other in a wire harness to be mounted in a car, an insulating cover of each electric wire is peeled to expose each core thereof, and exposed portions of the cores are connected to each other by welding, soldering or with a pressure terminal to form a connecting part. When the connecting part is covered with water, the cores and the pressure terminal are corroded. Thus in the wire harness disposed at an engine room side which is a region into which water penetrates, a waterproof structure is formed at the connecting part thereof.
As a waterproof structure having the above-described construction, as disclosed in Japanese Patent Application Laid-Open No. 4-334917, the present applicant proposed a waterproof structure of the connecting part shown in FIG. 14. In the above-described waterproof structure, the insulating cover 1 of required electric wires w1, w2 constructing the wire harness is peeled to expose the cores 2, the exposed cores 2 are connected to each other with the pressure terminal 3 to form the connecting part 4, the connecting part 4 is embedded in the silicone 6 delivered to the waterproof film 5, and the waterproof film 5 and the auxiliary waterproof film 7 are wrapped around the connecting part 4.
When the cores 2 are connected to each other with the pressure terminal 3 as described above, the number of electric wires which can be connected is not large. Thus even though the silicone 6 has a high viscosity, waterproofness can be accomplished by filling the silicone 6 between the cores 2.
But in forming the connecting part by connecting a large number of the cores to each other by ultrasonic welding, resistance welding, soldering or the like, the silicone 6 cannot be filled in the entire spaces between the cores 2 when the silicone 6 has a high viscosity. Therefore to fill the silicone 6 in a large number of spaces between the cores 2, it is necessary to decrease the viscosity of the silicone 6. When the silicone 6 having a low viscosity is applied to and filled in the spaces between the cores 2, the above-described waterproof structure has a problem that the silicone 6 drops or oozes from the films 5, 7 in wrapping the films 5, 7 around the connecting part. No problem occurs if the oozed silicone 6 solidifies. But leaving the silicone 6 until it solidifies makes the work efficiency low.
Patent document 1: Japanese Patent Application Laid-Open No. 4-334917